Process for breaking petroleum emulsions



Patented Mar. 28,

No Drawing.

9 Claims.

This invention relates to the treatment of emulsions'of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the water.

The main object of our invention is to provide a novel process for resolving petroleum emulF sions of the water-in-oil type that are commonly referred to as out oil,"roily oil, emulsified oil," etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a, more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

Another object of our invention is to provide an economical and rapid process for separating emulsions' which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsi flcation under the conditions just mentioned is of significant value in removing impurities, particularly inorganic salts from pipeline oil.

The demulsifler or demulsifying. agent employed in our process consists of a sub-resinous or semi-resinous product obtained by reaction between a polybasic-carboxy acid or its equivalent, such as the anhydride, and a hydroxylated esteramide of the kind hereinafter described. Said hydroxylated esteramide is of the kind in which the amido acyl radical is derived from a monocarboxy acid having not over carbon atoms and the oxyacyl radical is characterized by being derived from a monocarboxy detergentforming acid having at least 8 and not more than 32 carbon atoms.

It is well known that certain monocarboxy organic acids containing eight carbon atoms or more, and not more than 32-carbon atoms, are characterized by the factthat they combine with alkalies to produce soap or soap-like materials. fatty acids, resin acids, petroleum acids,-etc. For the sake of convenience, these acids will be indicated by the formula R'COO H. Certain derivatives of detergent-forming acids react with alkali to produce soap or soap-like materials, and are the obvious equivalent of the imchanged or unmodified detergent-forming acids; for instance, instead of fatty acids, one might employ the chlorinated fatty acids. Instead of the resin acids, one might employ the hydrogenated resin acids.

Instead of naphthenic acids, one might employ brominatednaphthenic acids, etc.

The fatty acids are of the type commonly referred to as higher-fatty acids; and of course, this is also true in regard to derivatives of the kind indicated, insofar that such derivatives are obtained from higher fatty acids. The petroleum These detergent-forming acids include,

Application December 27, 1941, Serial N0. 424,649

thenic acids, but also acids obtained by the oxidation of wax, paraflin, etc. as many as '32 carbon atoms. For instance. see U. S. Patent No. 2,242,837, dated May 20, 1941, to Shields.

Although any of the high molal monocarboxy' 'mulsifying agents are obtained from unsaturated fatty acids having 18 carbon atoms. Such unsaturated fatty acids include the higher fatty acids. such as oleic acid, ricinoleic acid, linoleic acid, linolenic acid, etc. One may employ mixed fatty acids, as, for example, the fatty acids obtained by hydrolysis of cottonseed oil, soyabean ofl, corn oil. etc. Our preferred demulsifier is obtained from unsaturated fatty acids, and mores specially, unsaturated fatty acids containing a hydroxyl radical or unsaturated fatty acids which have been subjected to oxidation or oxyalkylation, such as oxyethylation. I

The esteramides. of the kind herein described may be obtained in any conventional manner. They are usually derived from the low molal acids themselves; but if desirable, the functionalequivalents, such as the anhydrides, acyl chlorides, or other derivatives, may be employed. Suitable acids include, of course, acetic acid, propionic acid, butyric acid, valeric acid, etc. The amide of v such low molal acid may be treated with an oxyalkylenaOH,

Actually, thealkylene radical might represent I an equivalent divalent radical, in which thecarbon atom chain is interrupted at least once by acids include not only naturally-occurring naph- Having obtained a bis(hydroxyalkyl) amide of the kind described, such compound can then be D alkylen'e.0H I A procedure that UNITED STATES PATENT r-orr cs i Such acids may have is frequently more I pta s p y the reaction between a low f imolal acid such as acetic acid, and a material of, i I I the kind exemplified by diethanolamine, dipr'o w' panolamina'orthe like; ,Forthesakeof brevitm. I

referencehe'reafter'will be made largely to dieth- 1, anolamine and aceticacid, althoughother suitable reactants have already beendescribed. The I 4 method of 'manufaoturingesteramides is so well: I known that no further description is required: but. for convenienc theiollowlng example is 1 given in. substantially verbatim form, as it ap-j pearsin. 13.5. Patent No.. 2,238,928, dated Ap il, 1 22, 1941, to Cahnand Harris: I i 1 Example A 1 1 (11' 224 grams of methyl acetate (3. moles) :and i Z 210' grams of 'diethanolamine (2. moles) were. i s

mixed together, two layers iorming at first, the. v -mixturebecoming rhomogeneous massafter. a v "short time.The'mixturewas'refluxedfor 19* I hour at which time 90% .ofthe ditthanolarninev 1 had reacted. Aportion ofthe reaction: mixture. 1

"was subjectedtc-avacuum of fi millimetersat'fiflt a I 1C:,in-orderto.driveofl thevolatile materiahta. I i f the unreacted methylacetate and the methyl 9.1-

' 'cohol which was formed duringv the reaction.

The residue',upon titration, showed a content of mi of I fi ha j l a the renewing formula? CHr-C-N C2H4OH (2) 51.0 grams (A mole) of the acetic acid amide of diethanolamine produced as described in part 1 hereof, and 38.0 grams (V; mole) of lauric acid were heated together for minutes at approximately 200 C., while passing carbon Illustrating somewhat similar types of reactions, see (U. S. Patent No. 2,238,902, dated April 22, 1941, to Katzman and Harris, and also U. 8. Patent No. 2,257,183, dated April 30, 1941, to Munz and Troskan) In view of what has been said, it will be obvious that hydroxylated esteramides of the kind herein employed as reactants, may be obtained in various manners, including those described in the I I 4.64%.of freedlethanolamine: To192i5sramsof: I this residue, 34.? grams'of methyl acetatewere I l g s "added and the mixture: was refluxed; for 3 /2 f I I hours.) The resultingreaction product was then I I freed from itslow boiling constituentaioe, the i I I I 1 1 methyl alcohol and unreacted methyl acetate, by I I i v maintairiiing the mass at 7il= G.', under-a pressure y oifimillimeters. The-residue contained approx.- I i inratelyG.8% 'otunre'acted dieth'anolamine, based 1 "upon a determination of alkalinity of said i i j residue by titration The product was a light yet- I I I 1 l 1 low colored jyrunsolublein water; andcontained I a@ compound which was essentially the acetic; acid Z i as I I f tyr of a;

- such .hydroxylate d. esters, reference .is made to i I I thefoliowingiormulasi,j,

l 1' not:

acyl radicals all contain at least 8 and not more that 32 carbon atoms and are apt to contain 18 carbon atoms. R"CO is the acyl radical derived from a nonhydroxylated monocarbpxy detergent-forming acid, particularly an unsatur- A suitable alkylamine, or an alicyclic amine, or an patents previously mentioned. As illustrating ated acid, such as oleic acid, linolenic acid, etc. It is understood, of course, that a mixture of fatty acids might be employed instead of a single fatty acid. R' is a hydrocarbon radical having 4 to 12 carbon atoms.

In examining the above formulas, it is to be noted that comparable products might be obtainable from monobutanolamine, dibutanolamine, monopropanolamine, dipropanolamlne, monoglycerylamine, diglycerylamine, or the like, instead of being derived fromhnonoethanolamine or diethanolamine. Similarly, the products shown in the last two formulas are derived from tris(hydroxymethyl) amino methane. Similar derivatives may be derived from z-amino-z-ethyl- 1,3-propanediol and 2-amino-2-methyl-L3 propanediol.

The hydroxylated esteramides may, of course, be derived in any other suitable way, such as reaction with ammonia, followed by .oxyethylation, or some other suitable process. Thus, the low molal acids themselves, or, if desirable, the functional equivalents, such as the anhydrides, acyl chlorides, or other derivatives, may be reacted with ammonia, or a primary amine, such as any aralkylamine, to give the amide or substituted amide; in any event, a compound containing at I representsthef lfQ Z acid radical derived from: an acid hav n fi car- I bon; atoms or, less, such asacetic; propionic; bui 1 p j etc. tomx'c oreprlesents the lacylf radical I l I i nydroxylated acid, suchas ricinoleic acid, j v I y t ms acid, or: similar acids obtained. by i 1 i i f 1 oxidation, such as hl'ownoleicacidi or acids obi i l i 1 l tainedby the hydrolysis of blown olein. such y least one amino hydrogen atom. Suitable amines include butylamine, amylamine, cotylamine, decylamine, cyclohexylamine, benzylamine, phenylamine, etc. Generally speaking, when an amine is used instead of ammonia for reaction with a low molal acid, one must employ a hydroxylated detergent-forming acid, such as ricinoleic acid, in order to insure an available alcoholic hydroiwl group for subsequent reaction with the polybasic carboxy acid or its equivalent.

This is readily understandable by considering the reaction involving acetic acid and butylamine. The substituted amide soobtained can be' treated with ethylene oxide, and then reacted with 'oleic acid to give a substituted esteramide. Such substituted "esteramide, however; is not rcactive toward phthalic anhydride'by esterification reactiongin view of the absence of analcoholic hydroxyl radical. If, however, ricinoleic acid is employed as the reactant to supply the high molal oxyacyl radical, then the hydroxyl radical which is part of the ricinoleyl radical would serve as a reactive functionfor combina tion with phthalic anhydride or the like by esteriflcation. Lactic acid or the like might supply an'alcoholic hydroxyl radical.

An alternate procedure in case such com-' pounds are derived from butylamine, cyclohexylamine, benzylamine, or the like, is to use glycid or the like as an oxyalkylating agent, thus introducing at least two hydroxyl radicals, one of which may be employed for esterification with oleic acid, and the other one, for esterification with phthalic acid or the like.

The simpler procedure is to prepare the amide from ammonia, and such amide of a low molal acid may be treated with an oxy-alkylating agent, such as ethylene oxide, propylene oxide, butylene oxide, glycid, or the like, to produce a compound of the following type:

, fl) alkylene.0H

RCN

alkylene. O 11 Actually, the alkylene radical might represent an equivalent divalent radical in which the carbon atom chain is interrupted at least once by oxygen; i. e., the low molal amide, instead of being treated with two moles of ethylene oxide or the like, might be treated with four moles or six moles of ethylene oxide, or even more.

In any event, the reaction of the hydroxylated esteramide of the kind described with a polybasic carboxy acid or its functional equivalent, such as the anhydride, is awell-known reaction and is nothing more or less than an esteriflcation reaction of the kind employed to produce phthalated castor 01-1, phthalated ricinoleoamide, etc. For instance, common comparable reactions are described in U. S. Patent No. 1,976,602, to De Groote, Keiser, and Adams, dated October 9. 1934, and U. S. Patent No. 2,078,652, to De Groote and Keiser, dated April 27, 1937.

Briefly stated, the molar combinations of the reactions selected depend upon the available number of hydroxyl groups and may be illustrated by the following examples:

Example 1 One pound mole of the esteramide derived by reaction between equimolar portions of bis(hydroxyethyl) acetamide and ricinoleic acid, is heated with one poundmole 01' phthalic anhydride at approximately 145-165 C., until esterification is complete, as indicated by the substantial elimination of one alcoholic hydroxyl radical. The product so obtained has one 'free hydroxyl radical and one free carboxyl radical.

. Example 2 The product is prepared in the same manner as described in the previous example, except that the substituted acetamide is derived from oleic acid instead of ricinoleic acid.

Exampl s 1 I The same procedure is followed as in Example 1, except that two moles of phthalic-anhydride are employed instead of one mole, and the final esterification'productis characterizedby the sub.- stantial absence ofany free'hydroxyl radical and by the presence of-two free carboxylradicals.' v 1 Example 4 Tris(hydroxymethyl) aminomethane is reacted with acetic acid to give a comparable substituted acetamide. Such acetamide is reacted'with ricinoleic acid to give an esteramide. Such esteram= ide .is substitutedin Examples 1 and 3, preceding.

I Example 5 scribed in Example 4, preceding, is reacted with oleic acid to give the corresponding esteramide. Such esteramide is converted into an esterified product inthe manner described in Example 2, preceding.

- Example 6 Acetic acid is reacted with monoethanolamine to give the corresponding hydroxylated amide. Such amide is then esterified with ricinoleic'acid to give the esteramide. Such esteramide is reacted with phthalic anhydride in equimolar proportions by an esterification reaction to give the esterified final product having one free carboxyl radical.

Example 7 Acetic acid is converted into the substituted amide by reaction with amylamine vand then treated'with two moles of ethylene oxide to give the hydroxylated amide. Such amide is then reacted with ricinoleic acid to give the esteram- Such esteramide is then reacted with phthalic anhydride i equimolar proportions to give the final product having a free carboxyl radical.

Example 8 In the preceding examples, wherein amylamine is used as a reactant, cyclohexylamine or benzylamine is substituted.

' Example 9 In the preceding examples, where oleic acid is employed to introduce an acyloxy radical, naphthenic acids, resin acids, or oxidized acids are substituted.

, Example 10 In the preceding examples, where phthalic anhydride is used, maleic anhydride or oxalic acid is employed. In such instances where oxalic acidv is employed, it is desirable to use a lower temperature, in view of the fact that oxalic acid. or most of its functional equivalents, decompose at atemperature as high as or thereabouts, and instead a temperature of 1051l2 0. should be employed. Such lower temperature recuires longer time for esteriflcation to take place.

Esterification can be conducted in the usual manner, simplyemploying heat to drive off'th'e water formed. In some instances, where an anhydride is employed, water may not be formed. If desired, one may pass a dried, inert gas, such as dried nitrogen gas, through the mass to hasten esterification'. Esteriflcation is also hastenedat times by the presence of a mere trace of a suitable acid, such as benzene sulfonic acid. In other instances the reaction is most suitably conducted in the presence of an inert high boiling solvent, such as xylene. The xylene is continuously distilled under a reflux condenser, condensed by such condenser, and returned to the reaction chamber through a trap. The xylene vapors carry off the water, which is removed after being condensed by the trap. This is a conventional procedure, commonly employed in this type or similar types of reaction.

Although we prefer to use phthalic anhydride as the most desirable source of the polybasic carboxy acid, one may use other polybasic carboxy acids or their anhydrides, such as succinic, malic, fumaric, citric, maleic, adipic, tartaric, glutaric, diphenic, naphthalic, oxalic, pimelic, suberic, azelaic, sebacic, etc. Naturally, a simple derivative of a polybasic acid, such as chlorophthalic acid, can be used as advantageously as phthalic acid itself, although there is no added advantage in the use of the more costly chemical compounds.

In view of the large number of reactants and types of materials described, it may be well to note those which we particularly prefer. It has been pointed out that we prefer to use unsaturated fatty acids as the source of the high molal 'acyloxy radical, and particularly the hydoxylated fatty acids commonly available, to wit, ricinoleic acid. We prefer to use phthalic. acid, maleic acid, or their anhydrides, or oxalic acid as the source of the polybasic carboxy acid. We

This is indicated by the following:

(Y.X) (0H)1u (Y.X) @(COOH) w (OH) ,w(YX) (COOH) n" in which q indicates a small whole number (one in the case of a monomer, and probably not over .20 and usually less than 10), and in and n indicate the number 1 or. more, and nt', and 11 indicate zero or a small or moderately-sized whole number, such as zero, one or more, but in any event, probably a number not in excess of 10-15. Naturally, each residual hydroxyl could combine with a phthalic acid body or its equivalent, or with a similar compound derived from a tribasic acid, such as citric acid; and in such event, there would be a large number of free or uncombinedcarboxyl radicals present, possibly 20 or more. Actually, the preferable type of reagent would be more apt to include less than 20, and in fact, less than 10 free hydroxyl radicals. It is not necessary to remark that the residual carboxyl radicals can be permitted to remain as such, or can be neutralized in any suitable manner, such as conversion into salts, esters, amides, amino esters, or any other suitable form. Usually, such conversion into salt form would be by means of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, ammonium hydroxide, amylamine, butanolamine, ethanolamine, diethanolamine, triethanolamine, cyclohexanolamine, benzylamine, aniline, toluidine, etc. Conversion into the'ester would be'by means of a monohydric alcohol, such prefer to use acetic acid or its equivalent as the Y'(OH)n, where n indicates the number 1 or more, and if a polybasic acid body be indicated by the formula X(COOH)n, where 11. indicates the number 2 or more, then the reaction between a monohydric alcohol and a polybasic acid will result in a compound which may be indicated by the following formula: YX(CO0H)11', wherein n indicates the number 1 or more, and which is in 1 reality a contraction of a more elaborate structural formula, in which X and Y are joined by a carboxyl radical or residue. Assuming, however, as would 'be true in the majority of cases, that the alcohol actually would be a polyhydric alcohol, and that the acid body would be polybasic. in nature, for instance, if one employed a diphthalate of a polyhydroxylated ester amide of the kind previously described, then examination reveals that the formula might result in a combination, in which there were neither residual carboxyl radicals, nor residual hydroxyl radicals, or might result in compounds in which there were residual hydroxyl radicals, and no residual carboxyl radicals, :or compounds where there might be residual carboxyl radicals and no residual hydroxyl radicals; or there might be both.

as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, decyl alcohol, ethylene glycol, diethylene glycol, glycerol, diglycerol, triethylene glycol, or the like. One could employ an amino alcohol so as to produce an ester.

We have found, however, as suggested, that the most suitable products are sub-resinous, semiresinous, or balsam-like products, and are preferably derived from polyhydroxylated reactants, i. e., polyhydroxylated esteramides. We have found that such products are soluble to a fairly definite extent; for instance, at least 5% in some solvent such as water, alcohol, benzene, dichlorethyl ether, acetone, cresylic acid, or the like. This is simply another way of stating that it is preferable, if the product be one of the sub-resins, which are commonly referred to as an A resin, or B resin, as distinguished from a C resin, which is a highly infusible, insoluble resin (see Ellis, "Chemistry of Synthetic Resins," 1935, page 852, et seq.)

In recapitulating what has been said previously, the sub-resinous, semi-resinous, or balsamlike product herein contemplated may be indicated by the following formula:

' coon)..."

( )n"( y i') 000.2%," in which the characters have their previous significance, and 11' represents a small whole number not greater than 5, and :0 represents a small whole number not greater than 5;. Z represents a hydrogen ion equivalent, such as a metallic atom, organic radical, etc.,

It will be noted that compounds of the type just described having at least one. hydrophobe nucleus are designated as'being "polar" when there is present eitheran unesterifled hydroxyl radical, or an unesterified carboxyl radical, or

both. Wehave foundthat the polar type of material is by'far the most eflective for demulsiflcation, and 'it'is our preference to use such type.

Indeed; this particular type is so much more effective for demulsification than the non-polar type; that it may be considered in es'sencean invention within an"inventijon,

of such radical'inthe selected compound; instead of an amino hydrogenatom, results in markedly greater efiectiveness as a demulsi'fier. 'One possible explanation may reside in the fact that the presence of an amino hydrogen atom or the presence-of two "amino hydrogen atoms, ordim'ay*= contribute to association in the -'presence of -'hydroxylatedcompounds, to a greater ex'tentth'an when an acyl radical of the kind described 'is present as a substituent for an amino hydrogen atom. Regardless of whatever the I such, or after dilution with any suitable solvent,

such as water; petroleum hydrocarbons, such as gasoline, kerosene, stove oil; a coal tar product, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents, suchv as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similar,- ly, the material or materials employedas the demulsifying agent of our process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, .said material or materials maybe used alone, or'in admixture with other suitable well known classes of demulsifying agents.

' limited oilsolubility. However, since such reagents are sometimes used in a ratio oil to 10,000, or 1 to 20,000, or even 1 to 30,000. such an apparent insolubility in oil and water is not significant, because said reagents undoubtedly have solubility within the concentration employed. This same fact is true in regard to the material or materials employed as the demulsifying agent of our process.

We desire to point out that the superiority of the reagent or demulsifying agent contemplated in our process'is based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described will find comparativelylimited application, so far as the majority of oil field emulsions are concerned; but we have found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or atfso low -a cost with the demulsifying agents heretofore available.

In practising our process forresolvin'g petroleum emulsions of the water-in-oil type, a treat- 'ing agent or demulsifying agent of the kind above described is brought intofcontact'with' or caused to act upon the emulsion to bejtreated, in any of the various ways, or. by any of the various apparatus now generally used to. resolve 'orbreak petroleum'eniulsions with a chemical reagent, theabove procedure beingused either alone, or in combination with "other' demulsifying, procedure, such as the electrical dehydration process.

,Having thus described our inventipn, what we claim a'sn'ew and des'ireto secure Letters Patent is of the water-in-oil type, which consists in sub- ,iecting the emulsion to the action of a demulsifier comprising a sub-resinous esterification product of the following formula type:

(OH),.(Y,'X,')

in which a and y are small whole numbers not greater than 10 and m, n, and m are small whole numbers not over 10,-and including zero; Z is an acidic hydrogen atom equivalent; and X is a residue derived from a polybasic carboxy acid; and Y is a residue derived from a hydroxylated esteramide containing (a) one amidolinked acyl radical derived from a carboxy acid having not over 5 carbon atoms and free from an alcoholic hydroxyl radical; and (b) at least one acyloxy radical derived from a monocarboxy detergent-forming acid having at least 8 and not more than 32 carbon atoms, and linked by a divalent aliphatic radical to the amido nitrogen atom.

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action'of a demulsifier comprising a polar sub-resinous esterification product of the following formula type:

coon)" 0H)'.(Y.'x.

in which a:' and y are-small whole numbers not greater than 10 and m, n, and m' are small whole numbers not over 10, and including zero; Z is an acidic hydrogen atom equivalent; and X is I a residue derived from a polybasic carboxy acid; and Y is a residue derived from a hydroxylated esteramide containing (a) one amido-linked acyl radical derived from a carboxy acid having not over 5 carbon atoms and free from an alcoholic hydroxyl radical; and (b) at least one acyloxy radical derived from a monocarboxy detergentforming acid having at least 8 and not more than 32 carbon atoms, and'linked by a divalent aliphatic radical to theamido nitrogen atom.

3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in sub .lecting the emulsion to the action of a demulsifier comprising a polar sub-resinou esterifica- I tion product of the following formula type:

(coon )n( I' s') l. A process for breakingpetroleur'n in which 2: and y are small whole numbers not greater than 10, and m, n, and m are small whole numbers not over II, and including zero; Z is an acidic hydrogen atom equivalent; and X is a residue derived from a polybasic carboxy acid; and Y is a residue derived from a hydroxylated ester amide containing (a) one amide-linked acyl radical derived from a car- 7 boxy acid having not over carbon atoms and in which :c' and y are small whole numbers not greater than and m, n, and m are small "whole numbers not over 10, and including zero; Zis an acidic hydrogen atom equivalent; and X is a residue derived from a polybasic carboxy acid; and Y is a residue derived from a hydroxylated esteramide containing (a) one amido linked acyl radical derived from a carboxy acid havingnot over '5 carbon atoms and free from an alcoholic hydroxyl radical; and (b) at least one acylom radical derived from a higher unsaturated fatty acid having at least 8 and not more than 32 carbon atoms, and linked by a divalent aliphatic radical to the amido nitrogen atom.

5. A process for breaking petroleum emulsions oi the water-in-oil type. which consists in sub- Jeeting the emulsion to the action of a demulsiiier comprising a polar sub-resinous esteriflcation product of the following formula type:

numbers not over 10, and including zero; Z is an acidic hydrogen atom equivalent; and x is a residue derived from a polybasic carboiry acid; and Y is a residue derived from a hydroxylated esteramide containing (a) one amido-linked acyl radical derived from a carbon acid having not over 5 carbon atoms and i'ree from an alcoholic hydroxyl radical; and (b) at least one ricinoleyl oxy radical, and linked by a divalent aliphatic radical to the amido-nitrogen atom.

6. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifler comprising a polar sub-resinous esterification product of the following formula type:

greater than 10 and m, n, and m are small whole numbers not over 10, and including zero; Z is an acidic hydrogen atom equivalent; and X is a residue derived from a dibasic carboxy acid; and

l in which :r' and y are small whole numbers not i Y is a residue derived from a hydroxylated esteramide containing (a) one amido-linked acyl radical derived from a carboxy acid having not over V 5 carbon atoms and free from an alcoholic hydroxyl radical; and (b) at lea-stone ricinoleyl oxy radical, and linked by a divalent aliphatic radical to the amido nitrogen atom. a

7. A process for breaking petroleumlemuisions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifler comprising a polar sub-resinous esteriilca-' tion product of the following formula type;

coon).

( lfl w z v ooo.z) in.which :c' and y are small whole numbers not greater than 10 and m, n, and m'- are small whole 8. A process for breaking petroleum emulsions of the'water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifler comprising a polar sub-resinous esteriflcation product of the following formula type:

(coon)...

( mana e) in which an and y are small whole numbers not greater than 10 and m, n, and m are small whole numbers not over 10, and including zero; Z is an acidic hydrogen atom equivalent; and X is a residue derived from maleic acid; and Yis a residue derived from a hydroxylated esteramide containing (a) one amido-linked'acyl radical derived from a carboxy acid having not over 5 carbon atoms and free from an alcoholic hydroxyl radical; and (b) at least one derived from a ricinoleyl oxy radical, and linked by a divalent aliphatic radical to the amido nitrogen atom.

9. A process for breaking petroleum emulsions of the water-in-oil type,'- which-consistsin subjecting the emulsion to the action of ,a demuisifler comprising a polar sub-resinous esteriflcation product of the followingformula type:

' coon).n

(0n)..(Y,'x,-)

in which'z' and y are small whole numbers not greater than 10 and m, n, and m are small whole numbers not over 10, and including zero; Z is an acidic hydrogen atom equivalent; and X is a residue derived from oxalic acid; and Y is a residue derived from a hydroxylated esteramide containing (a) one amido-linked acyl radical derived from a carboxy acid having not over 5 carbon atoms; and free from-an alcoholic hydroxyl radical; and (b) at least one ricinoleyl oily radical, and linked by a divalent aliphatic radical to 

